U Class Submarines

Built to replace the 'H' boats, mainly as training boats, the original simple design of the 'U' class made it suitable only for anti-submarine training. In that role, they would not need to be armed, but this idea was soon changed to make them able to undertake war patrols.

The pre-war vessels were fitted with 2 external and 4 internal torpedo tubes, and the hull and casing forward of the conning tower was reinforced to allow installation of a small deck gun. At the start of the war, the Royal Navy decided to build more of this type of boat, and twelve identical units were ordered under the 1939 Supplementary Programme. After the first of this programme (Unique, Upholder, Upright and Utmost) were built, however, the external tubes were omitted. Eventually, another 41 boats were ordered, but ony 34 were completed. The contracts for seven (P81 - P87) were cancelled and replaced by seven boats of the V Class. The design became more streamlined, as the 'V' class replaced the 'U' - note the differences on the diagrams.

As individual boats the U Class lagged behind contemporary designs in other navies in terms of speed, range, armament etc and the layout, designed for unarmed boats, was more cramped than most other classes in the war. There was no guncrew and ammunitions hatch, so guncrews had to compete with bridge crew to get out of the boat and bring the gun to action - this slowed down the operation considerably, both for surfacing and diving, but, in the event, gun actions were rarely carried out by the U or V Class. (Unity and Undine were never fitted with a gun and consequently had 6 less in their crews).

On the other hand, there were some compensations with the design - the speed of building to a settled design, which gave the necessary numbers to make good the shortfall in individual power, manoeuvrability both dived and on the surface, ease of repair and general safety. Due to their size, shortage of reload torpedoes, small gun and lack of range, they were not deployed in the East in any number. Their main operating areas were the North Sea and Mediterranean, where these disadvantages were less important.

Nineteen of these submarines became war losses, six in the Atlantic and North Sea and 13 in the Mediterranean. Another boat - Untamed - sank in May 1943, but was salvaged, refitted and re-named Vitality.

The V class were a modification of the U design, but being of partly welded construction they were able to dive deeper. Construction was much reduced when the war in the Mediterranean eased off, and stopped altogether when VE-Day arrived. Four of the class operated in the Mediterranean, three of which (Virtue, Vivid and Vigorous) went on to operate in the Far East in 1944/45, though they must have been the most uncomfortable of all naval vessels in that area, due to the extreme humidity. They were joined in the East by Vox and Voracious. Of interest, all the V class were built by Vickers Armstrong, either at Barrow or on the Tyne.

Due to political decisions and the need for major economies, most of the U-class and V-class were scrapped by 1950, though in many cases they were hardly more than six or seven years old. Many were loaned to other navies and became temporary, reserve, members of the RN on their return, mainly in the mid-1950s, while those which were sold or transferred to Norway - Venturer (Utstein), Viking (Utvær), Variance (Utsira), Varne (Ula), Votary (Uthaug) - survived well into the 1960s.

Some technical information about the Paxman diesels can be found here.

A new book - "The History of the British U Class Submarine" by Derek Walters was published in Jan 2005. It can be purchased online at Pen and Sword.